Example where FILTER is no substitute for HAVING

[divral]

Here are two queries I am dealing with (stripped of some irrelevant parts):

Query 1: Hand-made query that shows pairs of tied winners of an Oscar.
The relevant part is that the HAVING clause works - the pairs of sets of people only occur once thanks to the ordering.

Query 2: Query made using templates. Instead of HAVING, FILTER is used but has no effect.

This example appears in the benchmark I am working on, so it would be great if FILTER worked here, too.
Maybe it is related to this issue and has something to do with how labels are handled.

[divral]

I also stumbled upon this related query in which the FILTER seems to have an effect: Query 3
However, it sometimes seems to use the wrong order (e.g., "Richard de Rochemont" < "Eddie Selzer").
This query also returns 11, 12 or 13 results when run multiple times, depending on the order of the elements in GROUP_CONCAT, an issue which I made another post for.

Maybe this additional example will be useful to figure out what is happening inside QLever. Sorry for not providing a minimal example.